Institut de Chimie de Picardie FR CNRS 3085


Theoretical and experimental studies of chitin nanocrystals treated with ionic liquid or deep eutectic solvent to afford nanochitosan sheets,

Ferreira Funes, C.; Bouvier, B.; Cézard, C.; Fuentealba, C.; Jamali, A.; Courty, M.; Hadad, C.; Nguyen Van Nhien, A.

J. Mol. Liq. 2023, 375, 121350.

Chitin nanocrystals have gained growing interest due to their many excellent properties, however the higher crystallinity of these nano-rod-shaped particles is a major hindering factor in preparation of nanochitosans with low degree of acetylation (DA). Here we studied the effect of the ionic liquid 1-ethyl-3-methylimidazolium acetate (IL) and deep eutectic solvent (choline chloride:lactic acid) (DES) pretreatments of chitin nanocrystals (NCChits) before the deacetylation step using both experimental and theoretical approaches. The results showed that the ionic liquid pretreatment was able to partially disrupt the crystalline structure leading to a lower DA (18.2 %) after two cycles of deacetylation reaction. DES pretreatment, however, was unable to disturb the intra- and intermolecular hydrogen bonds, resulting in a DA of 73.6 % similar to that of unpretreated chitin nanocrystals (73.2 %). SEM images of chitin nanocrystals pretreated with ionic liquid showed that the crystals can rearrange into sheets. Molecular simulations reveal the detailed mechanism of chitin nanocrystal dissociation, in which the combination of a net molecular charge and hydrogen-bonding groups on a single scaffold (as is the case for [C2mim] and [OAc]) plays a paramount role. These results can open the way to afford controlled nanochitosan sheets from chitin nanocrystals.

Copper-uptake mediated by an ecofriendly zwitterionic ionic liquid: A new challenge for a cleaner bioeconomy,

Vuillemin, M. E.; Waterlot, C.; Verdin, A.; Laclef, S.; Cézard, C.; Lesur, D.; Sarazin, C.; Courcot, D.; Hadad, C.; Husson, E.; Van Nhien, A. N.

Journal of Environmental Sciences 2022.

This study aims to investigate the ability of an imidazolium biobased Zwitterionic Ionic Liquids (ZILs) in enhancing the phytoavailability of copper from garden (G) and vineyard (V) soils using the model plant ryegrass. Uncontaminated and artificially contaminated CuSO4 soils, unamended and ZIL-amended soil modalities were designed. The copper/ZIL molar ratio (1/4) introduced was rationally established based on molecular modeling and on the maximal copper concentration in artificially contaminated soil. Higher accumulation of copper in the shoots was detected for the uncontaminated and copper contaminated ZIL amended V soils (18.9 and 23.3 mg.kg−1, respectively) contrary to G soils together with a ZIL concentration of around 3% w/w detected by LC-MS analyses. These data evidenced a Cu-accumulation improvement of 38 and 66% compared to non-amended V soils (13.6 and 13.9 mg.kg−1 respectively). ZIL would be mainly present under Cu(II)-ZIL4 complexes in the shoots. The impact on the chemical composition of shoot were also studied. The results show that depending on the soils modalitity, the presence of free copper and/or ZIL led to different chemical compositions in lignin and monomeric sugar contents. In the biorefinery context, performances of enzymatic hydrolysis of shoots were also related to the presence of both ZIL and copper under free or complex forms. Ecotoxicity assessment of the vineyard soil samples indicated that the quantity of copper and ZIL remaining in the soils had no significant toxicity. ZIL amendment in a copper-contaminated soil was demonstrated as being a promising way to promote the valorization of phytoremediation plants.

The formulation of a CMC binder/silicon composite anode for Li-ion batteries: from molecular effects of ball milling on polymer chains to consequences on electrochemical performances,

Ndour, M.; Bonnet, J.-P.; Cavalaglio, S.; Lombard, T.; Courty, M.; Aymard, L.; Przybylski, C.; Bonnet, V.

Materials Advances 2022.

The semi-synthetic polysaccharide carboxymethylcellulose (CMC) is one of the most studied and effective polymer binders for silicon-based anodes in Li-ion batteries. The formulation of the corresponding composite negative electrode with an appropriate mixture of electroactive silicon, a CMC binder and a carbon additive is mandatory to ensure a good electrical conductivity. Blending is commonly realized by a highly energetic ball milling treatment of these three aforementioned components. This type of mixing reduces the size of the obtained particles and can also potentially agglomerate them. Morever, it allows the formation of a nanostructured mixture which is essential for both the silicon activation and to achieve good electrochemical performance. However, such strong treatment can also cause a significant degradation of the polymer chains, as we have recently demonstrated for polyacrylic acid (PAA). In the present work, the structural and chemical effects of this mechanical grinding on three commercial CMCs ranging from 90 to 700 kg mol−1 were investigated. All the polymers were characterized using SEC-MALLS, FTIR spectroscopy, MALDI-TOF mass spectrometry and TGA-MS thermal analysis. In all cases, a huge average molecular weight decrease was noticed, leading to the appearance of a bimodal distribution with low (52–72 kg mol−1) to very low molecular weight populations (1–1.8 kg mol−1). From these results, two formulations of a negative electrode were compared, one with ball milling of the three compounds and another one including only ball milling steps for silicon and carbon. After the correlation of the characteristics of this negative electrode composite with the electrochemical results, it was demonstrated that a high number of functions for supramolecular or covalent linkages are keypoints of the herein anode performance. Low molecular weight CMC derivatives (about 64 kg mol−1) obtained by ball milling treatment led to higher stability of the electrode.

Start-up G+Lyte - Trophée de l'innovation dans la catégorie transition énergétique

La start-up G+LYTE, soutenue par le CNRS et CNRS Innovation est lauréate du Trophée de l'innovation dans la catégorie innovation transition énergétique !
Ce prix lui a été décerné par l'agence d'innovation Hauts-de-France Innovation

New Lipidyl-Cyclodextrins Obtained by Ring Opening of Methyl Oleate Epoxide Using Ball Milling,

Oliva, E.; Mathiron, D.; Rigaud, S.; Monflier, E.; Sevin, E.; Bricout, H.; Tilloy, S.; Gosselet, F.; Fenart, L.; Bonnet, V.; Pilard, S.; Djedaini-Pilard, F.

Biomolecules 2020, 10, 339.

Bearing grafts based on fatty esters derivatives, lipidyl-cyclodextrins (L-CDs) are compounds able to form water-soluble nano-objects. In this context, bicatenary biobased lipidic-cyclodextrins of low DS were easily synthesized from a fatty ester epoxide by means of alternative methods (ball-milling conditions, use of enzymes). The ring opening reaction of methyl oleate epoxide needs ball-milling and is highly specific of cyclodextrins in solventless conditions. L-CDs are thus composed of complex mixtures that were deciphered by an extensive structural analysis using mainly mass spectrometry and NMR spectroscopy. In addition, as part of their potential use as vectors of active drugs, these products were submitted to an integrity study on in vitro model of the blood-brain-barrier (BBB) and the intestinal epithelium. No toxicity has been observed, suggesting that applications for the vectorization of active ingredients can be expected.

Straightforward extraction and selective bioconversion of high purity chitin from Bombyx eri larva: Toward an integrated insect biorefinery,

Huet, G.; Hadad, C.; Husson, E.; Laclef, S.; Lambertyn, V.; Araya Farias, M.; Jamali, A.; Courty, M.; Alayoubi, R.; Gosselin, I.; Sarazin, C.; Van Nhien, A. N.

Carbohydr. Polym. 2020, 228, 115382.

Chitins of different purity grades (45%, 89.7% and 93.3%) were efficiently extracted from Bombyx eri larva and fully physico-chemically characterized. Compared to commercially available and extracted α-chitin from shrimp shell, the collected data showed that insect chitins had similar characteristics in terms of crystallographic structures (α-chitin), thermal stability and degree of acetylation (>87%). The major differences lay in the crystallinity indexes (66% vs 75% for shrimp chitin) and in the morphological structures. Furthermore, low ash contents were determined for the insect chitins (1.90% vs 21.73% for shrimp chitin), making this chitin extraction and purification easier, which is highly valuable for an industrial application. Indeed, after only one step (deproteinization), the obtained chitin from Bombyx eri showed higher purity grade than the one extracted from shrimp shells under the same conditions. Insect chitins were then subjected to room temperature ionic liquid (RTIL) pretreatment prior to enzymatic degradation and presented a higher enzymatic digestibility compared to commercial one whatever their purity grade and would be thus a more relevant source for the selective production of N-acetyl-D-glucosamine (899.2 mg/g of chitin-2 steps vs 760 mg/g of chitin com). Moreover, for the first time, the fermentescibility of chitin hydrolysates was demonstrated with Scheffersomyces stipitis used as ethanologenic microorganism.

Glycocluster Tetrahydroxamic Acids Exhibiting Unprecedented Inhibition of Pseudomonas aeruginosa Biofilms,

Taouai, M.; Chakroun, K.; Sommer, R.; Michaud, G.; Giacalone, D.; Ben Maaouia, M. A.; Vallin-Butruille, A.; Mathiron, D.; Abidi, R.; Darbre, T.; Cragg, P. J.; Mullie, C.; Reymond, J. L.; O'Toole, G. A.; Benazza, M.

J. Med. Chem. 2019.

Opportunistic Gram-negative Pseudomonas aeruginosa uses adhesins (e.g., LecA and LecB lectins, type VI pili and flagella) and iron to invade host cells with the formation of a biofilm, a thick barrier that protects bacteria from drugs and host immune system. Hindering iron uptake and disrupting adhesins' function could be a relevant antipseudomonal strategy. To test this hypothesis, we designed an iron-chelating glycocluster incorporating a tetrahydroxamic acid and alpha-l-fucose bearing linker to interfere with both iron uptake and the glycan recognition process involving the LecB lectin. Iron depletion led to increased production of the siderophore pyoverdine by P. aeruginosa to counteract the loss of iron uptake, and strong biofilm inhibition was observed not only with the alpha-l-fucocluster (72%), but also with its alpha-d-manno (84%), and alpha-d-gluco (92%) counterparts used as negative controls. This unprecedented finding suggests that both LecB and biofilm inhibition are closely related to the presence of hydroxamic acid groups.

Nitroxide-Grafted Nanometric Metal Oxides for the Catalytic Oxidation of Sugar,

Omri, M.; Becuwe, M.; Courty, M.; Pourceau, G.; Wadouachi, A.

ACS Applied Nano Materials 2019, 2, 5200-5205.

A new series of ([2,2,6,6-tetramethylpiperidin-1-yl]oxy) (TEMPO) catalysts supported on nanometric metal oxides (TiO2, AlO2, CeO2) and their efficiency for sugar oxidation are herein described. The preparation of such hybrid catalysts was carried out by modification of a metal oxide surface with a monolayer of phosphonic linker bearing a TEMPO radical. All prepared catalysts were carefully characterized by diffuse reflectance Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and transmission electron microscopy. The efficiency of these new hybrid TEMPO supported materials for sugar oxidation was evaluated on methyl α-d-glucoside, as a model carbohydrate. The three hybrid catalysts showed high selectivity, activity, and stability, suggesting a promising potential for rapidly obtaining acid sugar derivatives.